Rock-drilling engine.



G. ANDERSSON.

ROCK DRILLING ENGINE.

APPLICATION FILED MAR.2| 191s.

Patented May 29, 1917.

L xx/ IE gTAIEd PATENT FFIUE.

GUSTAF ANDERSSON, OF STOCKHOLM, SWEDEN, ASSIGNOR T0 NYA AKTIEBOLAGE'I ATLAS, OF STOCKHOLM, SWEDEN, A CORPORATION OF SWEDEN.

BOCK-IDRILLIN G ENGINE.

To all whom it may concern:

Be it known that I, Gnsrar ANDnnssoN, a citizen of the Kingdom of Sweden, residing at Stockholm, Sweden, have invented new and useful Improvements in Rock-Drilling Engines, of which the following is a specification.

This invention relates to rock drilling engines of the kind in which water under pressure is forced through the hollow bit into the bore-hole in order to remove dust therefrom.

It is well known in such engines to introduce the water into the hollow bit by means of a nozzle rigidly secured to the bit holder, and to prevent leakage of water between the bit and the bit holder by means of a packing of india rubber or the like disposed between the said nozzle and the bit. Experience has proved that the life of such nozzles is very short, this being due to the fact that the nozzle on account of the violent oscillations of the bit is subjected to stresses which in a very short time result in the nozzle breaking off.

The object of the present invention is to remove the said inconvenience, and the in vention consists, chiefly, in that the nozzle is loosely inserted in a recessor boring in the bit holder, in which it is free to oscillate in the longitudinal direction of the bit within limits suflicient to prevent the jams or jerks caused by the oscillations of the bit from acting in any detrimental way upon the nozzle, the latter being retained in the said recess by means of a nut or any other similar or suitable means.

In this device it is necessary to prevent the water from leaking between the nozzle and the inner wall of the said recess, and for this purpose I arrange the above mentioned packing in such a manner that it fits tightly not only against the bit but also against the side walls of a recess formed in the inner end of the nozzle.

In the accompanying drawing I have shown one embodiment of my invention. Figure 1 shows a longitudinal section of the fore end of a rock drilling engine, and Fig. 2 shows a cross-section on line A.B of Fig. 1.

Referring to the drawing, 1 indlcates the fore end of the cylinder of the engine, 2 the bit holder and 3 the bit. The latter Specification of Letters Patent.

Patented May $9, 1911?.

Application filed March 2, 1916. Serial No. 81,726.

has in usual manner a longitudinal channel t and a side channel 5 communicating therewith. In the bit holder 2 is formed a recess 6 in which is disposed a nozzle 7 to which a water hose is adapted to be connected in well known manner. As is clearly shown in the drawing there is a comparatively large play between the nozzle 7 and the inner side of the recess 6 so that the nozzle is free to oscillate relatively to the bit holder within certain limits. On account thereof the jams or jerks transmitted to the bit holder from the bit will not be capable of acting upon the nozzle in any det rimental degree and consequently the life of the said nozzle will be lengthened considerably. The nozzle may be retained in the recess 6 by means of a nut 8 or any other suitable means.

In the inner end of the nozzle is formed a recess or cavity 9 which is engaged by a perforated packing 10 of india rubber or similar material. This packing fits tightly against the bit and also against the side walls of the said recess so that the water flowing through the nozzle can not leak between the latter and the walls of the recess (3. In the upper side of the packing is formed a cup-shaped recess 11, on account whereof the pressure of the water flowing through the nozzle and the packing will keep the upper portion of the latter pressed against the wall of the recess 9.

The cross section of the packing is uni form or approximately uniform so that the packing can be displaced against the bit by the water pressure according as it is worn off on the end bearing against the bit.

Having now described my invention what I claim as new and desire to secure by Letters Patent is:

1. The combination of a bit holder having a recess, a nozzle secured and having a limited endwise movement in said recess; said nozzle being provided with a recess in its inner end, and apertured packing arranged in the latter recess and having a cupped side opposed to the bore of the nozzle.

2. In a rock drilling engine of the kind set forth, a nozzle loosely disposed in a re cess in the bit holder and formed with a recess at the inner end, means for retaining the nozzle in the first mentioned recess, and a packing fitting tightly against the bit and also against the Wall of the said recess of the nozzle, substantially as and for the purpose set forth.

8. In a rock drilling engine of the kind set forth a nozzle loosely disposed in a recess or boring in the bit holder and formed With a recess at the inner end, means for retaining the nozzle in the first mentioned recess, and a packing fitting tightly against the bit and also against the Wall of the said recess of the nozzle and being of substantially uniform cross-section area counted in a direction at right angles to the longitudinal direction of the bit, substantially as and for the purpose set forth.

l. The combination of a bit holder having a bit-receiving socket and a recess intersecting said socket, a nozzle secured and having a limited endwise movement in said recess, and an apertured packing held to the inner portion of the nozzle and arranged to contact with a bit in said socket.

5. The combination of a bit holder having a bit-receiving socket and a recess intersecting said socket, a nozzle secured and having a limited endwise movement in said recess, and apertured packing disposed in said recess and at the inner end of the bore in the nozzle and adapted to contact With a bit in said socket.

6. The combination of a bit holder having a bit-recoiving socket and a recess intersecting said socket, a nozzle secured and having a limited endwise movement in said recess, and cushioning means for easing said movements of said nozzle.

In testimony whereof I have signed my name in presence of two subscribing Witmesses.

GUSTAF ANDERSSON.

\Vitnesses ANDREW Nonnis,

K. E. lVnsone.

Copies of this patent may be obtained for five cents each, by addressing; the Commissioner of Patents, Washington, D. C. 

